Apparatus for conveying material through heat-treating furnaces



L. LARSON Feb. 24, 1931.

APPARATUS FOR CONVEYING MATERIAL THROUGH HEAT TREATING FURNACES Filed April 13, 1929 5 Sheets-Sheet l NW N w Leonard L anrbn tibial/wag L. LARSON Feb. 24, 1931.

APPARATUS FOR CONVEYING MATERIAL THROUGH HEAT TREATING FURNACES Filed April 13, 1929 3 Sheets-Sheet 2 Le on ard L 01 00:?

L. LARSON Feb. 24, 1.931.

Filed April 13, 1929 5 Sheets- Leonard Larson APPARATUS FOR CONVEYING MATERIAL THROUGH HEAT TREATING FURNACES Patented Feb. 24, 1931 UNITED srrvres PATENT. OFFICE LEONARD LARSON, OF MASSILLON, OHIO, ASSIGNOE, IBY MESNE ASSIGNMENTS, TO BE- PUBLIC STEEL COBPORATION, OF YOUN JERSEY GSTOWN, OHIO, A CORPORATION OF NEW APPARATUS FOR CONVEYING MATERIAL THROUGH HEAT-TREATING FURNACES Application filed April 13,

This invention relates in general to conveyors for moving metal sheets or bars through heat-treating furnaces, and more particularly to that type of conveyor which includes reciprocating members, commonly known as walking beams.

An object of the invention is to provide a novel conveyor of this type for economically transporting metal bars, sheets or the like through the furnace.

Another object of the invention is to provide a novel furnace construction fora-flording a maximum degree of protection of the bearings of the walking beams against the destructive action of the gases which are employed for heating the metal bars, sheets or the like.

A further object of the invention is to rovide means for permitting expansion of those parts of the conveyor which are exposed to the hot gases, and for controlling the effects of such expansion.

With the above and other objects in view, which will be more readil apparent as the nature of the invention is etter understood, the same consists in the novel construction, combination and arrangement of parts hereinafter more fully described, illustrated and claimed.

A preferred and practical embodiment of a the invention is shown in the accompanying Fig. 4 is a cross-section, taken on the line 4"4 of Figs. 1 and 3;

Fig. 5 is a view, artly in elevation and partly in section, ta on on the line 55 of Fig. 1 and showing the mechanism for imparting motion to the walking beams;

Fig. 6 is a fragmentary cross-section through the furnace, taken on the line 6-6 of Fig. 2;. V

Fig. 7 is a perspective view of one end of 1929. Serial No. 354,921.

the stationary beam and either end of the walking beam;

Fig. 8 is a perspective view of one of the joint supports for supporting and retaining one end of the stationary beams.

Fig. 9 is a perspective view of one of the expansion joints for supporting the other ends of the stationary beams.

Fig. 10 is a diagram showing the path of motion of the walking beams, the relative position of the stationary beams being indicated in dotted lines.

Referring more particularly to the drawings, wherein similar reference characters designate corresponding parts throughout the several figures, the present arrangement includes a furnace having a bottom 1, lower side walls 2, upper side walls 3 having portions 3a which overhang the lower side Walls, and a roof 4. The overhanging portions 3a of the upper side walls have spaced openings 3?) extending upwardly therethrough, and are partially'supported by spaced cross-walls 5. The walls 2 and 3 are also provided at spaced oints with openings 6, in which suitable urners may be inserted.

The walls of the furnace are maintained in proper position by means of a framework consisting of spaced upright channels 7 and cross-channels 8 secured to the upper ends thereof.

The upper edges of the walls 5 are provided at spaced points with integral piers 5a. The piers of alternate cross-walls are surmounted by joint supports 9 and the piers of the remaining cross-walls are surmounted by expansion joints 10.

Each joint support 9 comprises a base 90: having depending flanges 9b which are adapted to embrace the piers'5a, and oppositely .dis osed U-shaped members 90 spaced from eaci other to provide vertically extending slots 9d.

Each expansion joint 10 comprises a base 10a having de endin flanges 106 which are adapted to em race t e piers 5a of alternate crosswalls, and inverted L-shaped members 100 spaced from each other to provide alongitudinally extending slot 10d.

Stationary beams 11, T-shaped in cross-section, are notched near one end, as at 11a. In placing the beams 11 in position, one end of each beam is inserted in the expansion joint 10 in such manner that its web enters the slot 10d, and the notched end is then dropped into the space between the U-shaped members 90 of the joint supports 9 in such manner that the notches 11a embrace the U-shaped members, as shown in Fig. 3. Clearances, indicated at A, are provided between the ends of the beams which enter the expansion joints 10.

.It will be noted that the joint supports 9 prevent longitudinal displacement of the beams ll, but that the connection of successive beams at the expansion joints 10 permit the beams to expand freely when the furnace is heated. It will alsobe noted that the clearances A prevent the expansion of the beams 11 from being cumulative, as is the case in furnaces where no provision is made for clearance between beams.

Mounted upon the cross-channels 8, and extending substantially the full length furnace, are spaced H-beams 12. These beams support spaced brackets 13, upon which are pivotally mounted bell cranks 14.

The upper ends of the bell cranks 14 are pivotally secured to connecting rods 15, and

pivotally sus ended from the lower ends of the bell cran s, through the intermediary of links 16, are channel members 17, to which are rigidly secured stiff-legs 18, and pivotally secured links 19. The legs 18 and links 19 extend downwardly through the openings 3?) in the walls 3, and pivotally secured to the lower ends of these members are cradles 2.0.

The cradles 20 are in'the form of truss-like members, I-shaped in cross-section, and provided attheir upper edges with spaced joint supports 20a, which, except for the fact that they are integral with the cradles 20, are similar in construction to the joint supports 9.

Walking beams 21, notched at both ends in a manner similar to that in which one end of the stationary beams 11 is notched, are supported on the joint supports 20a in the same manner in which the notched ends of the stationary beams 11 are supported on thejoint supports 9, as clearly shown in'Figs. 3 and 4. supporting the walking beams serves to prevent their longitudinal displacement.

When the furnace is cold, the beams 21 are of such length that the links 19 occupy the angular positions shown in solid lines in Fig. 2, but whe'nthe furnace is heated. the expansion of these beams causes these links to'occupy the position shown in dotted lines in this figure. The notches in the ends of the beams 21, which are immediately to the right of the stiff-legs 18 are somewhat longer than the notches in the opposite ends of these beams or in any of the other beams, a provision which permits accumulated expansion of all of the walking beams between succes- Of the- It will be noted that this method of sive stiff-legs to be taken up at these points.

While I have shown six links 19 (three on each side of the furnace) between successive stiff-legs 18, it will be understood that any number of links, consistent with the amount of expansion to be taken up, may be provided between successive stiff-legs.-

Means for imparting motion to the walking beams may be located adjacent the fur- ,nace at any suitable point, and may include a motor 22 and a speed reducing unit 23. For the purpose of imparting vertical motion to the walking beams a cam 24 may be employed, and is secured to one end of the shaft of the reducing unit. This cam, through the intermediary of a lever 25, a link 26 and a crank arm 27, causes partial rotary motion of a shaft 28, which is mounted in'suitable bearings, secured to the H-beams 12. This rotary motion is translated intolhorizontal motion of the connecting rods 15 by means of gear segments 29.

Where the furnace is not of sufiicient length to cause undue stresses in the connecting rods 15, only two connecting rods (one on each side of the furnace) need be employed, and the use of the gear segments 29 dispensed with, but where the furnace is'of unusual length, as in a sheet normalizing furnace, four or more connecting rods may be employed, as shown in Fig. 2. In this case, additional gear segments 30, in mesh with the segments 29, may be employed to impart motion to the additional connecting rods. as will be readily understood by those skilled in the art.

For the purpose of imparting horizontal H-beams 12. This rotary motion is translated into horizontal motion of the channels 17 by means of lever arms 36 and links 37.

In the operation of the furnace, metal sheets or other material to be heat treated, is

conveyed through the furnace in successive steps by the walking beams. As indicated diagrammatically in Fig. 10, each successive step includes a lifting movement (1, caused by upward pivoting of the bell cranks 14, a horizontal transporting movement I), caused by horizontal movement of the channel members 17 and a depositing movement 0, caused bv downward pivoting of the bell cranks 14.

In the depositing movement, the sheets are deposited upon the stationary beams, and the walking beams are then returned to their initial position by a retracting movement (I, caused by reverse horizontal movement of the channel members 17. Since the sheets are deposited on the stationary beams on the downward movement 0, they are not returned to their initial position, but are advanced by stages through the furnace.

An important feature of the invention re sides in the fact that all of the moving bearings of the conveyor as well as the support ing members 18 and 19 are positioned outside of the heated zones of the furnace. This permits the bearings to be properly lubri cated and reduces maintenance costs. In fur naces, wherein the bearings are ex osed to the heat, proper lubrication of the earings is virtually impossible, and expansion of the bearings must be compensated by providing excessive clearances, which result in undue wear and seriously impair the operation of the conveyor. In addition, the excessive heat softens the metal of the bearings and thus causes them to wear out ra idly. It will also be noted. that portions 0 the overhanging walls 3a serve as bafiles between the hot gases in the heating chamber and the members 18 and 19, thereby protecting the latter from the destructive effects of such hot gases.

From the foregoing, it will be apparent that the present construction provides an arrangement which will fulfill the objects herein set forth, and provides a simple, practical and reliable means for conveying'material through a furnace.

Without further description, it is thought that the features and advantages of the invention will be readily apparent to those skilled in the art, and it will of course be understood that changes in the form, proportion and minor details of construction may be resorted to without departing from the scope of the appended claims.

Claims:

1. In combination with a furnace having side walls provided with openings extending vertically therethr'ough', means for conveying material through said furnace including reciprocating members, cradles for sup orting said reciprocating members, members or sup-- porting said cradles extending through said openings and connecting members secured to the upper ends of said supporting members.

2. A structure as defined in claim 1, in which the connecting members are positioned outside of the furnace.

3. A structure as defined in claim 1, in which the connecting members are-positioned outside of the furnace, and means for im parting vertical and horizontal movement to said connecting members.

4. A structure as defined in claim 1, in which the supporting members are pivotally secured to the cradles at their lower ends.

5. A structure as defined in claim 1, in which certain of said supporting members are pivotally secured to said connecting members at their upper ends. o 6. A structure as defined in claim 1, in which certain. of said supporting members are rigidly secured to said connecting members at their upper ends.

7. Apparatus for conveying material through a furnace including reciprocating members, cradles for supporting said reciprocating members, members for supporting said cradles and connecting members secured to the upper ends of said supporting members.

, 8. A structure as defined in. claim 7 in which the supporting members. are pivotally secured to the cradles at their lower ends.

9. A structure as defined in claim 7 in which certain of said supporting members are pivotally secured to said connecting members at their upper ends.

10. A structure as defined in claim 7, in which certain of said supporting members are rigidly secured to said connecting members at their upper ends.

11. A structure as defined in claim 7, and means for imparting vertical and horizontal movement to said connecting members.

12. In combination with a furnace, spaced cross-walls in said furnace, joint supports and expansion joints mounted respectively on alternate cross-walls and stationary members mounted on the supports and joints, the supports maintaining the members against longitudinal and lateral displacement, and the joints permitting longitudinal expansion of the members.

13. Apparatus for conveying. material through a furnace including members adapted to support and convey material through a furnace, cradles supporting said members, supports for the cradles and members secured to and connecting the upper ends of said cradle supporting member P 14. A structure as defined in claim 13, in which-the cradle supporting members are pivotally secured to t 1e cradles at their lower ends.

15. A structure as defined in claim 13, in which certain of said cradle supporting members are pivotally secured to said connecting members at their upper ends.

16. A structure as defined in claim 13, in which certain of said cradle supporting members are rigidly secured to said connecting members at their upper ends. i

17. A structure as defined in claim 13, in which certain of said cradle supporting members are pivotally secured to sand con necting members at their upper ends and the remaining cradle supporting members are rigidly secured to said connecting members at their .upper ends.

In testimony whereof I afiix my signature.

LEONARD LARSON. 

